The present invention relates to large rectangular balers and more particularly relates to knotter and needle drive arrangements for such balers.
The bales produced by large rectangular balers are bound by a plurality of transversely spaced loops of twine. In order to reduce the amount of twine which has to be pulled about the bale, and thus reduce the amount of frictional resistance required to be overcome in order to pull the twine, it is known to provide upper and lower sources of twine for producing the loops with the loops being tied together with two knots, one at each end of the bale. Two knots, one being at the upper front corner of a bale just completed and the other being at the upper rear corner of a bale just beginning to be formed, are tied during the same tying cycle.
An example of a baler having a knotting arrangement for producing two knots in each loop is disclosed in U.S. Pat. No. 4,108,062, issued on Aug. 22, 1978. In this patented structure, a knotter drive sprocket is continuously driven and is coupled so as to be connected to a knotter drive shaft by a one-way clutch that is intermittently actuated in response to a bale being completed. This drive arrangement is not completely satisfactory in that it is relatively complex and costly, and its speed of operation is dependent upon that of the drive for the plunger and/or pick-up.
According to the present invention there is provided an improved drive arrangement for the knotters of a baler for making large parallelepiped bales.
An object of the invention is to provide a knotter drive arrangement which is of a relatively simple, low cost design having independent and/or intermittent drive capabilities.
A more specific object of the invention is to provide a knotter drive arrangement which includes an independently powered, extensible motor that is coupled for causing rotation of a knotter drive shaft so as to effect one tying cycle through one stroke of the motor. In the preferred embodiment the motor is in the form of a hydraulic cylinder whose extension turns the knotter drive shaft slightly more than 360xc2x0.
Yet another object of the invention is to provide a knotter drive, as set forth in the immediately preceding object, that includes a one-way clutch for allowing the drive cylinder to be reset to its beginning position without effecting further rotation of the knotter drive shaft.
These and other objects of the invention will become apparent from a reading of the ensuing description together with the appended drawings.